Beneficiation of beryllium ores



I Patented Jan. 28, 1947 BENEFICIATION OF BERYLLIUM ORES James S. Kennedy and Robert G. OMeara, Rolla, Mo., assignors to the United States of America, as represented by the Secretary of Interior No Drawing. Application November 5, 1943, Serial No. 509,082

(Granted under the act of March 3,- 1883, as

12 Claims.

The invention described herein may be manufactured and used by or for the Government of the United States for governmental purposes without the payment to us of any royalty thereon in accordance with the provisions of the act of April 30, 1928 (Ch. 460, 45 Stat. L. 467).

This invention relates to the beneficiation of beryllium ores, and more particularly to the production of a beryllium concentrate from ores containing beryllium. minerals in admixture with a gangue of widely varying composifion.

Heretofore, attempts have been made to conmaterial or of surface altered material and a new process must be developed.

The principal beryllium ores are beryl, helvite and danalite. Beryl occurs in admixture with varying amounts of pegmatite, granitic veins, gneisses, slates and mica schists associated with such minerals as quartz, feldsparz, spodumene, amblygonite, micas, rutile, apatite, garnet, tourmaline, cassiterite and clays. Helvite and danalite occur in pegmatites, tactites, granites, g'neisses and in vein material with such minerals as magnetite, fluorite, garnet, hematite, chlorite and micas.

This invention provides a method by which the foregoing and other beryllium minerals can be concentrated from the above-mentioned and other gangue minerals regardless of their varying proportions or surface alteration.

In accordance with this invention, beryllium ores are beneficiated and a beryllium concentrate is produced by treating a comminuted beryllium ore with an acidicfluorine compound, thereafter admixing a mineral-filming reagent with the ore and then separating a filmed mineral by selective concentration thereof to yield a berylliumenriched concentrate.

The invention, while not limited to any particular theory of operation is believed to be suc cessful because of the cleaning or scouring action of the acidic fluorine compound upon the surfaces of the minerals in the beryllium ore. Thus,

amended April 30, 1928; 370 0. G. 757) it may be that an etching or other corrosive action occurs which improves the ability of mineral-filming reagents to film the desired minerals. After ,pretreating with the acidic fluorine compound, the beryllium may be separated by filming the ore with suitable reagents and concentrated ,by flotation, agglomerate-tabling or similar mineral concentrating procedures taking advantage of mineral filming.

Suitable beryllium ores are comminuted to a particle size suitable for the concentration step, preferably by stage grinding to minimize slime production. In general a particle size passing through a 20-to-65-mesh standard Tyler screen, is suitable for agglomerate-tabling procedures and a particle size passing through a -mesh screen and freed of minus 5 micron material, is preferable for flotation procedures.

Suitable fluorine compounds, preferably employed in amounts of from one to fifteen pounds thereof per ton of ore, are normally acidic fluorine compounds and compounds yielding the same under acidic conditions, such as for example, hydrofluoric acid, fluosilicic acid, fluoboric acid, hydrofluoboric acid, fluorides yielding hydrofluoric acid under acidic conditions, such as for example, sodium fluoride, potassium fluoride, calcium fluoride and similar fluorine compounds. When a fluoride not normally acidic is employed, a strong acid is employed in conjunction therewith, suitable acids being 'sulphuric, hydrochloric, nitric and similar strong mineral acids. After treatment with the acidic fluorine compound, preferably hydrofluoric acid, the beryllium ore may be sent directly to the concentration step but is preferably washed with an excess of water to remove excess acid and liberated materials and to de-slime the comminuted ore.

After treatment with hydrofluoric acid or similar acidic fluorine compounds, and if desired, after de-sliming and water-washing, the beryllium ore is thoroughly admixed with a mineralfilming reagent, preferably in amounts of from 0.2 to 2.0 pounds per ton of ore, adapted to the concentration procedure later to be employed.

Suitable mineral-filming reagents for employment in agglomerate-tabling concentration procedures are fuel oil, oleic acid, wood and coal tar creosotes, and the like. filming reagents include both the anionic type, in which the reagent ionizes in water tov give small cations and large, complicated water-repellant anions, and the cationic" type of flotation reagent in which the reagent ionizes in water to give small anions and large, complicated, water- Suitable flotation mineral repellant cations. Suitable anionic flotation reagents include oleic acid, stearic acid, lauric acid and the acids corresponding to vegetable and animal oils and fats such as those derived from coconut oil, castor oil, sesame oil, sunflower seed oil, whale oil, lard, garbage grease and similar naturally occurring vegetable and animal fats and oils, as well as the alkali metal soaps derived therefrom, for example, sodium oleate, -ste'arate, -laurate and the like. Suitable cationic flotation reagents include the acid salts of amines derived from the above-mentioned vegetable and animal fats, long chain quaternary ammonium halides, the ammonium salt of lauryl diethylene-glycol sulphate, dodecylamine hydrochloride, stearylamine hydrochloride, mixtures of the hydrochlorides of mono-n-octadecyl and mono-n-hexadecyl amines, trimethyl stearylammonium bromide, lauryl pyridinium iodides, other quaternary ammonium compounds and the like. 'As previously mentioned, the mineral concentration operation is chosen to accord with the reagents above described. In agglomerative tabling, the mineral is filmed with reagents best adapted to the production of agglomerates, then flowed across an inclinedtable having a. reciprocal motion and provided with a cross-wash of water, as in the well-known Wilfley table.

In carrying out beryllium ore concentration in accordance with this invention, the ground ore is mixed with sufiicient water to'form a pulp or slurry to which is added the acidic-fluorine compound, the resulting pulp is blunged, diluted with water, allowed to settle and the suspended slimes and supernatant liquor are separated by suitable means, such as decantation. This operation is repeated as many times as is necessary to secure complete de-sliming and acid removal. In some 25 acid per ton of feed for 30 minutes.

rials known to the flotation and agglomerate tabling art can be incorporated if desired.

The following examples illustrate how the invention may be carried out, but it is not re- 5 stricted thereto. Parts and percentages given are by weight unless otherwise designated:

EXAMPLE 1 Flotation of the beryl by means of ananlonic collector and refloatlng the beryl with a cationic collector in the presence of a mineral acid to depress the beryl from the tourmaline in a final cleaning step.Beryl1ium ore from a reject stockpile at the Ross Mine No. l, Custer, South Dakota, which contained 0.64 percent beryllium (calculated as BeO), or 5.3 percent beryl in a gangue of quartz, microcline, muscovite, schorlite, lithiophilite, feldspar, spodumene, amblygonite and cassiterite,-was crushed through IO-mesh,

was ground to minus IOU-mesh in stages, and

of 4'7 percent hydrofluoric acid for 15 minutes and again washed free from acid. The rougher concentrate was cleaned four times. The first two cleaners depressed the gangue other than tourmaline; the last two cleaners depressed the beryl from the tourmaline.

Operational data cases, where the ore contains after pre-treatment Product BB0 only an inconsequential amount of residual acid and slimes, the de-sliming and washing steps may 7 M4 be omitted. The pulp obtained is mixed with $5 5 suflicient water, preferably softened to avoid inf" Z :1 1: terference by insoluble soap formation and the g like, admixed with the necessary mineral-filming reagent, and the combination of ore, water and Hefldsvcalculawd -0 reagent is thoroughly conditioned. Thereafter Operational data Pounds per ton of iced Conditioners Cleaners Reagent Cleaners Rougher Rougher l 2 3 4 Hydrofluorlc acid (47 went; 0 eie act 0 54 0. 36 Pine il 0 18 0.18 Bulruricacld 2.0 2.0 a mnasa 0.8 0.8 1 o 7.0 7.3 2.0 2.0 iime, minutes 1 2 2 1 1 I A mixture of the hydrochlorides of mono-n-octadecyl amine and mono-n-hexedecyl amine, manufactured by Armor and Company, Chicago, Illinois.

the recovery of the beryllium minerals is eflected. 70

EXAMPLE 2 FLOTATION or BERYL ORE AND CLEANING 'ro Darnsss TOURMALINE AND OPAQUE MINERALS Beryllium ore, from the mines of the Black Hills Keystone Corporation, Keystone, South Da- 5 kota, which contained about 5.5 percent beryl,

Percent of (0.60 percent beryllium calculated as the oxide),

in a gangue composed principally of albite, mus- The first two cleaners depressed the gangue other than tourmaline. The second two cleaners depressed tourmaline from beryl.

Results of flotation Weight Analysis Percent oi Product percent percent B60 total BeO Beryl concentrate 4. 6 8. 72 59. 6 Tourmaline middling 9 5.28 7. 0 Middling.. l8. 1 .25 6.7 Telling 57. 9 12. 8 Slime. 14. 0 62 12.8 Mica 4.5 .18 1.2

Composite 100. 0 67 100. 0

Heads, analysis 06 Operational data Pounds per ton of ore Conditioners Reagent Cleaners 12 l 2 3 4 Rougher H drofluoric acid 47% HF) 9.2 2.3 2.3 Oleicacid Pine oil A. M. 118.5 B 0.08 0.08

pH 2.0 2.0 2.0 7.5 7.5 7.5 2.0 2.0 Time, minutes so 5 a 5 4 4 1 1 EXAMPLE 3 AGGLOMERATE TABLING OI BERYL OR! Results of agglomerate tabling of -1nesh fraction Weight Analysis Percent of Product percent percent Be'O total BeO Concentrate 8. 8 8. 48 85. 4 Tailing 91. 2 14 14. 6

Composite 100. o 87 100. o

Th minus 65-mesh fraction was conditioned with 4.6 pounds of hydrofluoric acid to the ton for 10 minutes. The sand was de-slimed and washed free from acid, pulped with 1.6 pounds g H ime, minutes or sodium oleate and 17.0 pounds of fuel oil to the ton, to agglomerate beryl. andtabledi.

Results of aaalomerate tablin a 0! minus ss-m sn' fraction Weight Analysis Peroentoi Pmdm percent percent 1360 to'talBeO Concentrate e. s e. 28 e1. 1 Tailing ee. 1 16 26. 0 sum 7. 1 .47 e. 3

Composite 100.0 .63 100.0

Combined results of agglomeration test We ht, Analysis, Percent 01 Product per cent percent BeO total BeO Total concentrate 7 2 6.97 78.8 Totaitailing 88.8 .15 19.0 a 20 Slime as .47 2.2

Composite 0 .70 100.0

Heads,snalysis .66

25 EXAMPLE 4 I FLOTATION or Hum-Damn more are One I Beryllium ore, rrom Iron Mountain, Winston, New Mexico, containing 1.44 percent beryllium calculated as the oxide, and approximately 35 ercent magnetite and other opaque minerals, 30 percent fluorite, 18 percent helvite, 9 percent sillimanite. and 8 percent of other minerals including chlorite, hematite, apophyllite, quartz, chalcedony, psilomelane, wad (altered danalite), pyrosmalite, clay minerals and calcite, was ground through 100-mesh and scrubbed with 18.4 pounds of hydrofluoric acid per ton of ore or 15 minutes. At the end or the conditioning period the acid was consumed and the pH of the. pulp was 7.5. A rougher concentrate was floated with 0.54 pound of oleic acid and 0.18 pound of pine oil per ton of ore. In this case no de-sliming and washing was required. The rougher concentrate was cleanedtwice and magnetite was separated from the concentrate on a low-intensity magnetic separator.

Results of flotation and magnetic separation Hydrofluoric acid (4% HF) Oleic acid Pine 011-.

In this particular case the ore contained fluorite and hydrochloric acid was substituted for hydrofluoric acid with satisfactory results both in flotation and agglomerate tabling. In three asglomerate tabling tests on the 14- to 20-mesh,

28- to 35-mesh and 35- to 48-mesh products of the ore ground through 14-mesh, concentrates contained 5.81, 6.66 and 3.58 percent BeO, respectively, and the tailings in the same order were 1.36, 1.54 and 1.72 percent. In a flotation test on the 100- to 200-mesh portion of the ore using the same reagents except that fuel oil was omitted, th concentrate contained 6.47 percent BeO and the tailing, 1.61 percent.

It is apparent from the foregoing description and examples that a desirable treatment has been provided whereby beryllium minerals can be concentrated from ores of extremely varying composition by treating or scouring with an acidic fluorine compound or compounds yielding the same under acidic conditions.

Various changes can be made in the detailed employment of the invention without departing from the spirit and scope thereof.

What is claimed is:

1. A process for the beneficiation of beryllium ores which comprises blunging a comminuted beryl ore in admixture with an equal weight of .water, with about 4.6 pounds of 47% hydrofluoric acid per ton of ore for 30 minutes, washing the treated ore with excess water and decanting the slimes until the ore pulp has a pH of 7.; admixing therewith per ton of ore about 0.54 pound of oleic acid and about 0.18 pound of pine oil, agitating and aerating the mixture to recover as a froth a rougher concentration containing beryl and tourmaline, again blunging the rougher concentrate with, per ton of ore, about 4.6 pounds of 47% hydrofluoric acid, washing the ore pulp free of acid with excess water, admixing with the pulp about 0.36 pound of oleic acid and 0.18 pound of pine oil per ton of ore, agitating and aerating the mixture to recover as a froth a mineral concentrate, repulping said concentrate with water, again agitating and aerating the pulp to recover as a froth a mineral concentrate, repulping said concentrate with water, admixing two pounds per ton of ore of sulfuric acid and 0.08 pound per ton of ore of a mixture of mono-n-octadecyl and mono-n-hexadecyl amine hydrochlorides, agitating and aerating at pH2 to separate a froth containing gangue minerals and removing a beryl concentrate from the residual pulp.

2. In the beneficiation of beryllium ores involving selective filming with a fatty acid reagent, the steps comprising treating such an ore with an acidic fluorine. compound and subjecting the thus-treated ore pulp to froth flotation in the presence of a higher fatty acid whereby a beryllium-enriched concentrate is produced.

3. In the beneficiation of beryllium ores involving selective filming with a fatty acid reagent, the steps comprising treating such an ore under acidic conditions with a fluorine compound and subjecting the thus-treated ore pulp to agglomerate tabling in the presence of a higher fatty acid whereby beryllium-enriched concentrate is produced.

4. In the beneficiation of beryllium ores involving selective filming with a fatty acid reagent, the steps comprising treating a comminuted beryllium ore in an aqueous medium with an acidic fluorine compound, and then washing said treated ore with excess water to remove slimes, subjecting the thus-treated ore pulp to froth flotation in the presence of a higher fatty acid whereby a beryllium-enriched concentrate is produced.

5. In the beneficiation of beryllium ores involving selective filming with a fatty acid reagent, the steps which comprise treating a comminuted beryllium ore in an aqueous medium under acidic conditions with a fluorine compound, and then washing the thus-treated orenwith excess water to remove sllmes, subjecting the thustreated ore pulp to froth flotation in the presence of a, higher fatty acid whereby a beryllium-enriched concentrate is produced.

6. In the beneficiation of beryllium ores involving selective fllming with a fatty acid reagent, the steps which comprise agitating a comminuted beryllium ore in the presence of aqueous hydrofluoric acid and then washing the thus-treated ore with excess water, subjecting the thus-treated ore pulp to froth flotation in the presence of a higher fatty acid whereby a beryllium-enriched concentrate is produced.

7. In the beneficiation of beryllium ores involving selective filming with a fatty acid reagent,

the steps comprising treating such an ore in an aqueous medium with from 1 to 15 pounds of an acidic fluorine compound per ton of ore, subjecting the thus-treated ore pulp to froth flotation in the presence of a higher fatty acid whereby a beryllium-enriched concentrate is produced.

8. In the beneficiation of beryllium ores involving selective fllming with a fatty acid reagent, the steps comprising treating such an ore in an aqueous medium at a pH of 1. to 6. with from 1 to 15 pounds of a fluorine compound per ton of ore, subjecting the thus-treated ore pulp to froth flotation in the presence of a higher fatty acid whereby a beryllium-enriched concentrate is produced.

9. A process for the beneficiation of beryllium ores which comprises treating a comminuted beryllium ore with an acidic fluorine compound, thereafter admixing a higher fatty acid mineralfllming reagent with the ore and then separating a filmed mineral by froth flotation to yield a beryllium-enriched concentrate.

10. A process for the beneficiation of beryllium ores which comprises treating a comminuted beryllium ore in an acidic aqueous medium with a fluorine compound from the group of fluorinecontaining acids and compounds yielding the same under acidic conditions, thereafter admixing with the ore a higher fatty acid mineral-filming reagent and then separating a filmed mineral by froth flotation to yield a beryllium-enriched concentrate.

11. A process for the beneficiation of beryllium ores which comprises treating a comminuted beryllium ore in an aqueous medium at a pH of 1. to 6. with from 1 to 15 pounds of an acidic fluorine compound per ton of ore, thereafter admixing with the ore from 0.2 to 2.0 pounds of a higher fatty acid mineral-filming reagent per ton of ore, and then separating a filmed mineral by froth flotation to yield a beryllium-enriched concentrate.

12. The process of claim 11 wherein the ore pulp after treatment with an acidic fluorine compound is deslimed and washed with excess water.

JAMES S. KENNEDY. ROBERT G. OMEARA. 

